OBJECTIVES: To estimate the health care costs, treatment patterns, and health care resource use in advanced ovarian cancer (aOC) patients receiving first line chemotherapy. METHODS: Incident aOC patients between 2000-2005 were identified from the linked Surveillance, Epidemiology and End-Results (SEER)/Medicare data file using an ICD-9 code 56.9 with a “distant” tumor in the SEER staging variable. Women ≥65 years at the time of aOC diagnosis (i.e. index date), with at least three months of data preceding the initial diagnosis were included. Subjects were followed from 30 days prior to index date until the first occurrence of the following: receipt of a 2nd line treatment given after a minimum of 90 days treatment free interval, death or the end of the Medicare claims data (i.e., December 2007). Measures of overall HRU included hospitalizations, outpatient visits, physician visits, hospice care, home healthcare, and skilled nursing facility utilization.   Costs of each HRU event were estimated by summing all Medicare payments, primary insurer payments, patient copayments and deductibles for services in the claims files. Average healthcare costs per event per patient (e.g. hospitalization) are calculated as total cost per event divided by number of patients with the event. RESULTS: A total of 3895 aOC subjects receiving first-line chemotherapy were included in the analysis. Mean age was 75 years. Carboplatin+paclitaxel (73%), carboplatin alone (8.5%), and carboplatin+docetaxel (7%) were the three most commonly used 1st line chemotherapeutic agents. The mean 1st line treatment duration was 128 days (SD 95.8). The rate of hospitalization was 1.5 per person-year. Mean hospitalization cost per patient was $12,997 (SD $10,499).  Mean SNF and Hospice Care costs per patient were $7,509 (SD $7,171) and $7,025 (SD $11,370) respectively. CONCLUSIONS:  Carboplatin-paclitxel combination was the most commonly used first line chemotherapeutic regimen.  In aOC patients, hospitalization costs were substantial in women with aOC receiving 1st line chemotherapy.